[4] Throughout the 1990s, a close relationship between cetaceans and mesonychians, an extinct group of cursorial, wolf-like ungulates, was generally accepted based on morphological analyses.

[5] Through a principal components analysis Gingerich 2003 demonstrated that Rodhocetus had trunk and limb proportions similar to the Russian desman, a foot-powered swimmer using its tail mainly as a rudder.

From this Gingerich concluded that Rodhocetus was swimming mostly at the surface by alternate strokes of its hind feet, and that it was insulated by fur rather than blubber, as are Dorudon and modern cetaceans, which made it buoyant and incapable of deep diving.

[6] The holotype of R. kasrani, GSP-UM 3012 found in 1992, was described by Gingerich et al. 1994: a cranium with two dentaries, most of the vertebral column as far as the anterior tail (C2–C7; T1–13; L1–6, S1–4, Ca1–4), most ribs, parts of the sternum, both hip bones, and a left femur.

Dating from about 47 million years ago, they are one of a series of recent discoveries, including the pakicetids, which have thrown considerable light on the previously mysterious evolutionary origin of whales.